Agricultural mowers are designed to cut forage crops including grass and grain in widths of from about eight feet up to twelve feet or more for each pass through a field. Cuttings are thrown from such mowers and lie behind the mowing equipment as it passes through a field. Depending on designed capabilities mowers can either throw cuttings to lie essentially directly behind the equipment in scattered patterns across the width cut by the mower, i.e., in a swath, or they can include deflectors made from, for example, sheet metal, also known as tin ware, for directing cuttings to lie in a continuous pile having a restricted width smaller than the width cut by the mower that extends directly behind the mowing equipment, i.e., in a windrow. Harvesting is made easier when cuttings are windrowed because harvester equipment can pick up windrowed cuttings without having to rake laterally from the sides or without having to make numerous passes over a field in order to harvest all cuttings spread over a field.
Today harvester capacities have so increased that harvesting single windrows of cuttings is a substantial underutilization of equipment capacity. In point of fact, currently available harvesters and bailers can adequately collect doubled windrows even when cuttings are windrowed from mowers cutting fourteen foot widths.
Windrow mergers are equipment of various types now being used to double windrows in order to take advantage of increased harvester capacities. For example, after mowing and windrowing, a windrow merger of one type is attached to a tractor. This equipment is used before, or as a part of the harvesting process, to rake up cuttings in a windrow on one side of the tractor and with a conveyor belt move and throw cuttings onto or beside a windrow on the other side of the tractor. If this windrow merger is used as part of the harvesting process, it must be attached to the front of the tractor and a harvester and baler or forage box must be attached to the back of the tractor. This front mounted windrow merger doubles windrows harvested by the back mounted harvester. Examples of such windrow mergers include the models 1150 and 1160 sold by the Gehl Company, West Bend, Wis.
Using a windrow merger in simultaneous combination with a harvester is an attempt at achieving time efficiency if windrows have not been previously doubled. However, combining pushing, pulling and powering disparate pieces of windrow merging and harvesting equipment causes undo increased wear and tear on tractors. In the alternative using a windrow merger of this type without a harvester at least doubles the time required to harvest cuttings. Additionally raking tends to mix rocks and other foreign objects in with cuttings in the doubled windrow. Raking also causes leaf loss in legume crops resulting in poorer quality hay or forage.
Attempts have also been made to provide windrow doubling attachments for use on mowers. A specific example of such a windrow doubling attachment is described in U.S. Pat. No. 4,590,751 issued to Stephenson. The described windrow doubling attachment is mounted from the mower frame at three points. As so mounted the windrow doubling attachment is supposed to be hung from the mower and entirely supported off the ground. To accomplish windrow doubling the described attachment includes in combination a complex mechanical system for shuttling a belt conveyor from side-to-side that is used to move cuttings. In one position for the shuttled belt conveyer, cuttings are thrown from the mower onto the belt conveyor that then laterally moves the cuttings away from the mower to one side. In another shuttled position for the belt conveyor, a portion of the cuttings are thrown from the mower onto the ground and the remainder of the thrown cuttings fall onto the belt conveyor that then moves and drops them on the ground with those originally thrown from the mower. As mounted on mowers the described windrow doubler receives cuttings that have been initially deflected by mower tin ware for windrowing irrespective of whether or not the described windrow doubler is used with the mower. The combination of mower windrowing tin ware and the described windrow doubler equipment unavoidably constrains flow of cuttings to the point that when the mower cuts through thick crops the increased density of cuttings clogs in the region of the mower tin ware and the described windrow doubler. The clogged cuttings must then be manually removed which is both an inefficient and dangerous operation. Such windrow doubling equipment because of its exclusive attachment to the back of mower frames also unavoidably causes undue wear and tear to mower frames. Additionally mowers can become unbalanced because this windrow doubling equipment is both mounted and suspended only from the aft portion of mowers without having counterbalancing weight positioned on the forward portion of mowers. Further the windrow doubling equipment described here includes substantial mechanical complexity in devices and structures required to shuttle the belt conveyor system from side-to-side.